...lift the log, somewhat toward the stump end of the center of gravity. ...The nearly balanced top end can then be picked up and swung onto a sawbuck and the hoist lowered to put the log on the other one.
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That worked better with my very mobile tripods than with the jib crane on the truck, where I positioned the log by guessing where the sling should be and dragging the log in the saw-dulling sand of the trail. Putting a big log on two widely spaced sawbucks with one hoist of limited height was tricky enough that I bought a second lever hoist and made another tripod for it.
Ideally the first sawbuck (or the hoist sling) would be positioned where the big end was one cut mark short of dropping, and when the cutting passed it the rest barely balanced on the next sawbuck. In practice I was close enough if I could lift the small end by hand and placed the first sawbuck a few marks past the hoist sling. That allowed the most cuts with the least hoisting and repositioning. The hoist initially raised the big end, then stayed loosely attached as long as possible in case a sawbuck failed. With experience I could come close, particularly after practice on the sawmill where the ton or more log needed to be balanced under the overhead hoist
Usually the trees that died before reaching the crown were small enough to pull the remainder onto the second sawbuck with one hand once the cutting reached it.